----------------------------------- metachief Sun Feb 17, 2008 6:31 pm rotation ----------------------------------- Could someone tell me how to make a picture rotate according to the direction my mouse is pointing to? ----------------------------------- Sean Sun Feb 17, 2008 6:35 pm Re: rotation ----------------------------------- Pic.Rotate to your Mouse X and Y variables? ----------------------------------- fishtastic Sun Feb 17, 2008 7:05 pm Re: rotation ----------------------------------- ah... i think i know what you mean. what you need is to figure out the mouse angle. based on the x,y coordinate of the picture and the coordinate of the mouse. View.Set ("offscreenonly") var x2, y2, mc : int loop cls mousewhere (x2, y2, mc) var d := Math.Distance (x2, y2, maxx div 2, maxx div 2) if d > 0 then var angle := arccosd ((x2 - maxx div 2) / d) if y2 - maxx div 2 < 0 then angle := 360 - angle end if Draw.ThickLine (maxx div 2, maxx div 2, x2, y2, 3,black) put angle : 2 : 2 View.Update end if end loop ----------------------------------- metachief Sun Feb 17, 2008 7:11 pm RE:rotation ----------------------------------- um..what i meant was , for example: if i have a triangle, i want one of the angles to point at the location of the mouse. So i know it has somethig to do with Pic.Rotate, but i am not sure. ----------------------------------- fishtastic Sun Feb 17, 2008 7:35 pm RE:rotation ----------------------------------- 1.draw a triangle 2.use pic.new to take a picture 3.figure out the angle of the mouse 4.use pic.rotate to create a rotated picture 5.draw the pic returned by pic.rotate ----------------------------------- metachief Sun Feb 17, 2008 7:41 pm RE:rotation ----------------------------------- thanks i got the consept , but how do i plug in the mouse coordinates as the angle? ----------------------------------- fishtastic Sun Feb 17, 2008 7:43 pm RE:rotation ----------------------------------- my code above ----------------------------------- Sean Sun Feb 17, 2008 7:43 pm Re: rotation ----------------------------------- Your Mouse X and Mouse Y would equal a position, then you would want one of your rotating angles to equal the mouses. ----------------------------------- metachief Sun Feb 17, 2008 7:50 pm RE:rotation ----------------------------------- Here's my code: var gun: array 0..35 of int gun (0) := Pic.FileNew ("gun.bmp") for angle : 0..35 gun(angle):= Pic.Rotate (gun (0),angle*10,player_x,player_y) end for Pic.Draw (gun(0), (player_x * 10)+4, (player_y * 20)+5, picMerge) i don't know how to make the mouse coordinates into the angle of the picture. PS: The code above doesn't work, because i ca't do math distance for some reason. ----------------------------------- metachief Sun Feb 17, 2008 8:20 pm rotation2 ----------------------------------- Me again. I tried, but i ran into another problem. This is my code: Mouse.Where (z,t,button) var d := Math.Distance (z, t, maxx div 2, maxx div 2) if d > 0 then var angle := arccosd ((z - maxx div 2) / d) if t - maxx div 2 < 0 then angle := 360 - angle end if gun (0) := Pic.FileNew ("gun.bmp") gun(0):= Pic.Rotate (gun(0),round(angle),px,py) end if Pic.Draw (gun(0), (px * 20)+4, (py * 20)+5, picMerge) View.Update The problem with it is that my picture doesn't stay in the same place, but instead when i move my mouse around it rotates in circles ----------------------------------- CodeMonkey2000 Sun Feb 17, 2008 8:20 pm RE:rotation ----------------------------------- For make a function called getAngle. This function will take the position of the mouse and the position of the picture and get the angle between them. Next when you draw the picture you will draw picture(calculated angle divided by 10). ----------------------------------- CodeMonkey2000 Sun Feb 17, 2008 8:22 pm RE:rotation2 ----------------------------------- Please stick to one thread. ----------------------------------- metachief Sun Feb 17, 2008 8:25 pm RE:rotation2 ----------------------------------- what difference does it make? By the way do u think u could help me ----------------------------------- CodeMonkey2000 Sun Feb 17, 2008 8:46 pm RE:rotation ----------------------------------- Basically you need to find the angle between the player and the mouse. To do this you will need to know some trigonometry. More specifically you need the tangent and tangent inverse functions. Now I assume that you are in grade 10 and thus have a limited knowledge of trig. So being the nice guy I am here is my angle function. fcn angle (px, py, tx, ty : int) : real var adjecent : real := tx - px var opposite : real := ty - py if adjecent = 0 and ty > py then result 90 elsif adjecent = 0 and ty px then result 0 end if if opposite = 0 and tx < px then result 180 end if if ty < py then if arctand (opposite / adjecent) > 0 then result 180 + arctand (opposite / adjecent) else result 360 + arctand (opposite / adjecent) end if result 180 + arctand (opposite / adjecent) else if arctand (opposite / adjecent) < 0 then result 180 + arctand (opposite / adjecent) else result arctand (opposite / adjecent) end if end if end angle Just pass in the player x,y and the mouse x,y and this function will return the angle. I programmed this when I was in grade 10, so this code is really messy and inefficient. And if you still don't know what to do, here is an example. ----------------------------------- fishtastic Sun Feb 17, 2008 8:59 pm RE:rotation ----------------------------------- metachief I already answered your question, dont drag more people in to answer the same question. you said "but how do i plug in the mouse coordinates as the angle?" i already answered it before you ask that. CodeMonkey2000 was nice enough to help, but read the reply before posting a new one. dont expect people to give you exactly what you need. ----------------------------------- ericfourfour Sun Feb 17, 2008 11:39 pm Re: rotation ----------------------------------- I didn't use any test cases so I'm unsure if it will give the correct angle but I think it does the best job explaining how to get the angle. % CAST rule. This is like grade 10 trig. % S|A % --- % T|C % Quadrant 1: all positive (x > 0, y > 0) % Quadrant 2: sin positive (x < 0, y > 0) % Quadrant 3: tan positive (x < 0, y < 0) % Quadrant 4: cos positive (x > 0, y < 0) % The start angle is always tan^-1(abs (y / x)). % Just add or subtract 180 or 360 to put it in the correct quadrant. % Translate to the origin then sub in x and y. fcn getAngle (x, y : real) : real if x > 0 then if y > 0 then % quadrant 1 result arctand (abs (y / x)) else % quadrant 2 result 180.0 - arctand (abs (y / x)) end if elsif x < 0 then if y > 0 then % quadrant 4 result 360.0 - arctand (abs (y / x)) else % quadrant 3 result 180.0 + arctand (abs (y / x)) end if else if y > 0 then % on upper y-axis result 90.0 else % on lower y-axis result 270.0 end if end if end getAngle If you have taken grade 10 math, this is stuff is in your notes. For more information: http://en.wikipedia.org/wiki/Cartesian_coordinate_system. ----------------------------------- OneOffDriveByPoster Mon Feb 18, 2008 9:32 am Re: rotation ----------------------------------- In many programming languages, there is an atan2(y, x) function for this. It is important to understand what goes behind it though--not all implementations work the same. ----------------------------------- metachief Mon Feb 18, 2008 10:09 am RE:rotation ----------------------------------- thank you very much guys, you were alot of help..sorry for making it a big deal, it's just im a beginner at this, and im trying to get ahead fast